| Challenger - Trieste | 07/26 15:00 | 25 | [215] Thomas Fabbiano v Lorenzo Giustino [235] | 3-6,4-6 | |
| Challenger - Todi | 07/13 11:00 | 25 | [472] Giovanni Fonio v Lorenzo Giustino [227] | 6-4,6-3 | |
| Challenger - Perugia | 07/06 11:10 | 25 | [325] Timofey Skatov v Lorenzo Giustino [228] | 1-6,7-6,6-0 | |
| Challenger - Porto | 06/29 11:25 | 25 | [228] Lorenzo Giustino v Frederico Ferreira Silva [176] | 4-6,6-4,3-6 | |
| Wimbledon | 06/22 11:35 | 14 | [215] Lorenzo Giustino v Illya Marchenko [155] | 5-7,6-7 | |
| Challenger - Almaty | 06/15 09:10 | 25 | [215] Lorenzo Giustino v Pavel Kotov [270] | 6-7,4-6 | |
| Challenger - Almaty | 06/07 05:35 | 25 | [178] Lorenzo Giustino v Timofey Skatov [399] | 4-6,6-3,2-6 | |
| Challenger - Biella | 06/03 11:30 | 26 | [237] Marco Trungelliti v Lorenzo Giustino [178] | 6-4,6-2 | |
| Challenger - Biella | 06/01 13:30 | 25 | Luca Nardi v Lorenzo Giustino | Retired | |
| French Open | 05/25 14:25 | 14 | [178] Lorenzo Giustino v Zhizhen Zhang [175] | 7-5,5-7,2-6 | |
| ATP - Geneva | 05/16 13:10 | 19 | [104] Pablo Cuevas v Lorenzo Giustino [174] | 6-2,6-4 | |
| ATP - Geneva | 05/15 11:00 | 14 | [174] Lorenzo Giustino v Peter Gojowczyk [132] | 6-2,6-3 | |
| Challenger - Biella | 05/04 08:00 | 25 | [242] Dimitar Kuzmanov v Lorenzo Giustino [175] | 6-3,1-6,6-3 | |
| Challenger - Biella | 05/04 08:00 | 25 | [208] Aleksandar Vukic v Lorenzo Giustino [175] | Cancelled | |
| Challenger - Rom | 04/29 14:40 | 26 | [210] Cem Ilkel v Lorenzo Giustino [174] | 6-4,6-2 | |
| Challenger - Rom | 04/27 12:25 | 25 | [174] Lorenzo Giustino v Juan P Varillas [150] | 6-1,7-5 | |
| Challenger - Rom | 04/23 13:05 | 27 | [179] Lorenzo Giustino v Vit Kopriva [287] | 6-1,5-7,3-6 | |
| Challenger - Rom | 04/22 09:00 | 26 | [179] Lorenzo Giustino v Sergiy Stakhovsky [211] | 6-4,6-4 | |
| Challenger - Rom | 04/21 09:00 | 25 | [179] Lorenzo Giustino v Filip Horansky [178] | 7-6,7-5 | |
| Challenger - Split | 04/13 15:20 | 25 | [204] Andrea Collarini v Lorenzo Giustino [168] | 6-4,6-4 | |
| ATP - Marbella | 04/05 10:00 | 19 | [135] Henri Laaksonen v Lorenzo Giustino [170] | 7-5,3-6,6-1 | |
| ATP - Marbella | 04/04 10:00 | 14 | [190] Roberto Marcora v Lorenzo Giustino [164] | 6-7,4-6 | |
| Challenger - Marbella | 03/30 09:00 | 25 | [196] Mario Vilella Martinez v Lorenzo Giustino [164] | 7-6,6-0 | |
| ATP - Miami | 03/22 16:00 | 14 | [204] Mitchell Krueger v Lorenzo Giustino [164] | 6-4,6-3 | |
| ATP - Dubai | 03/16 12:50 | 25 | [163] Lorenzo Giustino v Aljaz Bedene [59] | 4-6,3-6 | |
| ATP - Dubai | 03/14 07:00 | 19 | [96] Mikhail Kukushkin v Lorenzo Giustino [162] | 6-2,6-2 | |
| ATP - Dubai | 03/13 10:55 | 14 | [322] Andrea Vavassori v Lorenzo Giustino [162] | 3-6,3-6 | |
| Challenger - Biella | 03/11 10:30 | 26 | [216] Brayden Schnur v Lorenzo Giustino [162] | 6-4,6-2 | |
| Challenger - Biella | 03/09 15:05 | 25 | [162] Lorenzo Giustino v Yasutaka Uchiyama [109] | 7-5,6-4 | |
| Challenger - Gran Canaria | 03/02 10:00 | 25 | [160] Lorenzo Giustino v Enzo Couacaud [187] | 6-7,7-5,1-6 |
Lorenzo Giustino (Italian pronunciation: [loˈrɛntso dʒuˈstiːno]; born 10 September 1991, in Naples) is an Italian tennis player.
Giustino has a career-high ATP singles ranking of 127 achieved on 12 August 2019 and a career-high ATP doubles ranking of 311 achieved on 15 April 2019.
Giustino made his ATP main draw debut at the 2015 BRD Năstase Țiriac Trophy, where he qualified for the main draw.
Giustino made his Grand Slam debut at the 2020 Australian Open. He defeated Frenchman Corentin Moutet 0–6, 7–6 (7), 7–6 (3), 2–6, 18–16 in the first round of 2020 French Open as a first time main draw qualifier at this Major. The match was the second-longest in French Open history, lasting 6 hours, 5 minutes. It was his first ATP tour-level win.
He qualified for his first ATP 500 tournament at the 2021 Dubai Tennis Championships as a lucky loser receiving a bye into the second round after the withdrawal of tenth seed Borna Ćorić.
He qualified for his second ATP 500 at the 2023 Barcelona Open Banc Sabadell.